Abstract Poor medication adherence is a fundamental, unsolved obstacle preventing the real-world translation of clinical trial findings that have been shown to reduce diabetes-related complications in older adults. To realize these health benefits in clinical settings, we need interventions that lead to sustainable improvements in medication adherence. The use of mail-order pharmacies may represent such an approach, that overcomes financial and logistical barriers to medication acquisition and leads to improved medication adherence by older adults. The proposed career development award has 3 specific aims: 1) to evaluate whether the use of mail- order pharmacies as compared with local pharmacies is associated with greater adherence to diabetes-related medications (oral antiglycemics, antihypertensives, and HMGCoA reductase inhibitors (statins); a higher proportion of generic as compared to brand name diabetes-related medications; and lower out-of-pocket medication costs among Medicare Part D enrollees; 2) to develop low-literacy intervention materials intended to increase mail-order pharmacy use among low-income Part D enrollees and test them in a feasibility trial, and 3) to develop additional quantitative and qualitative research skills necessary to succeed as an independent investigator conducting translational research. Dr. Duru will work closely with his research mentors including Dr. Carol Mangione, the Principal Investigator of the UCLA Resource Center for Minority Aging Research (RCMAR), to conduct the proposed research. As part of the proposed career development plan, Dr. Duru will acquire skills in the use of statistical techniques, including instrumental variable analyses, to maximize causal inference in studies using observational data. He will apply these techniques in the analyses described in Specific Aim #1. He will also develop expertise in the area of healthcare implementation in real-world settings, and apply this in the activities described in Specific Aim #2. This proposed K award will provide Dr. Duru with the training and skills needed to become an independent investigator, conducting intervention research that results in tangible improvements in the health of vulnerable older adults.